POS1461 ADVANTAGES OF DOPPLER IN LABIAL SALIVARY GLAND ULTRA-HIGH FREQUENCY ULTRASOUND: CORRELATIONS WITH HISTOLOGICAL INFLAMMATION, pSS DIAGNOSIS, DISEASE ACTIVITY, AND PROGNOSIS
Authors: G. Fulvio, F. Ferro, R. Izzetti, G. Governato, S. Fonzetti, G. La Rocca, I. C. Navarro García, V. Donati, M. Mosca, C. Baldini
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Musculoskeletal Doppler US is currently used to estimate the level of inflammation and to differentiate between arthritis and degenerative disease. In addition, Doppler is associated with disease activity and damage, namely prognosis. Recently, a novel colour Doppler Score has been proposed for major salivary glands. However, clinical associations of salivary glands Doppler US are unclear, both in major salivary glands (MSG) and in labial salivary glands (LSG). <h3>Objectives</h3> To investigate potential associations between colour Doppler of LSG Ultra-High Frequency Ultrasound and histology, pSS diagnosis, clinical manifestations and prognosis. <h3>Methods</h3> From January 2021 to October 2022 consecutive patients, undergoing LSG biopsy, were enrolled in our cross-sectional study. LSG Ultra-High Frequency ultrasound (UHFUS) was performed with a 70 MHz probe, evaluating parenchymal inhomogeneity (score 0-3, as MSG four-grade OMERACT grey scale scoring system, GS-OMERACT) and vascularization (score 0-3, as MSG four-grade OMERACT colour Doppler scoring system, CD-OMERACT) and their sum (score 0-6, Total-OMERACT). Patients' histological, biological and clinical features were collected. ACR/EULAR 2016 criteria fulfilment was the gold standard for diagnosis. LSG biopsy with a Focus Score (FS) &gt;1 was considered positive. For statistical analysis, following tests were applied: Student's t test, Mann- Whitney U test, contingency table analysis, Spearman's correlation. Receiver operating characteristic analysis was calculated to assess the accuracy of UHFUS to predict histology inflammation and pSS diagnosis. <h3>Results</h3> 127 patients were enrolled: 61 pSS patients, 47 sicca controls and 20 sicca patients with other connective tissue diseases. GS-OMERACT predicted a positive biopsy with an area under the curve (AUC) =0.835. UHFUS inflammation prediction was increased considering both grey scale and colour Doppler (Total-OMERACT), with a sensitivity=80.4%, a Specificity=84.7% and an AUC raised to 0.875 (Figure 1A). In addition, CD-OMERACT revealed a higher accuracy for pSS diagnosis than GS-OMERACT (AUC 0.780 vs 0.735). Total-OMERACT score was characterised by a sensitivity of 78.7% and a specificity of 76.6% for pSS diagnosis (AUC 0.803, Figure 1B). Both GS-OMERACT and CD-OMERACT, in pSS patients, were correlated with serological activity: autoantibodies (SSA/Ro52, SSA/Ro60, SSB) IgG levels and Rheumatoid Factor. However, CD-OMERACT presented a stronger correlation than GS-OMERACT, and significantly correlated with low C3 and C4 (Table 1). Similarly, both GS and CD also correlated with total ESSDAI and separate lymph nodes, glandular and biological domains. The correlation observed was higher with Doppler signal than inhomogeneity. The latter also exhibited a significant correlation with renal activity. All 5 patients with LSG severe/atypical inflammatory infiltrate had GS-OMERACT score 3 and CD-OMERACT score 3 with a typical pattern: multiple very hypoechoic areas and high perilesional CD signal. <h3>Conclusion</h3> UHFUS Colour Doppler, combined with grey scale, allows a better detection of labial salivary glands inflammation. Compared to grey scale, CD offers a unique opportunity in patient's phenotyping, due to its higher correlation with disease activity and pSS serological hallmarks. Eventually, a high doppler signal could be a key feature to identify more severe/atypical inflammatory infiltrate thus allowing the early recognition of lymphoproliferative complications. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.